U.S. patent application number 10/268437 was filed with the patent office on 2003-03-27 for process for making non-particulate detergent product readily dispersible in water.
Invention is credited to Waynforth Angell, Adrian John, Zorb, Les Charles.
Application Number | 20030060394 10/268437 |
Document ID | / |
Family ID | 22177217 |
Filed Date | 2003-03-27 |
United States Patent
Application |
20030060394 |
Kind Code |
A1 |
Waynforth Angell, Adrian John ;
et al. |
March 27, 2003 |
Process for making non-particulate detergent product readily
dispersible in water
Abstract
A process for producing a water-dispersible non-particulate
detergent product includes the step of providing a particulate
detergent composition. The process further includes the step of
adding a flow aid to the particulate detergent composition in a
range of from about 0.1% to about 25% by weight of the particulate
detergent composition. The process then includes the step of
compacting the particulate detergent composition having the flow
aid by applying a pressure in an amount sufficient to form the
water-dispersible non-particulate detergent product having a
density of at least about 1000 g/l. This process enables the
manufacture of a rapidly dispersing non-particulate detergent
composition that sinks in water.
Inventors: |
Waynforth Angell, Adrian John;
(West Chester, OH) ; Zorb, Les Charles; (Loveland,
OH) |
Correspondence
Address: |
THE PROCTER & GAMBLE COMPANY
INTELLECTUAL PROPERTY DIVISION
WINTON HILL TECHNICAL CENTER - BOX 161
6110 CENTER HILL AVENUE
CINCINNATI
OH
45224
US
|
Family ID: |
22177217 |
Appl. No.: |
10/268437 |
Filed: |
October 10, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10268437 |
Oct 10, 2002 |
|
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09674000 |
Oct 25, 2000 |
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6495509 |
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Current U.S.
Class: |
510/446 ;
510/452; 510/507 |
Current CPC
Class: |
C11D 17/0073 20130101;
C11D 17/065 20130101; C11D 3/3942 20130101 |
Class at
Publication: |
510/446 ;
510/452; 510/507 |
International
Class: |
C11D 017/00 |
Claims
What is claimed is:
1. A process for producing a water-dispersible non-particulate
detergent product, comprising the steps of: (a) providing a
particulate detergent composition; (b) adding a flow aid to the
particulate detergent composition in a range of from about 0.1% to
about 25% by weight of the particulate detergent composition; and
(c) compacting the particulate detergent composition having the
flow aid by applying a pressure in an amount sufficient to form the
water-dispersible non-particulate detergent product having a
density of at least about 1000 g/l.
2. The process of claim 1 wherein the flow aid is added in an
amount in a range of from about 1% to about 15% by weight of the
particulate detergent composition.
3. The process of claim 2 wherein the flow aid is added in an
amount in a range of from about 1% to about 10% by weight of the
particulate detergent composition.
4. The process of claim 3 wherein the flow aid is added in an
amount of about 5% by weight of the particulate detergent
composition.
5. The process of claim 1 wherein the water-dispersible
non-particulate detergent product has at least about 5% greater
dispersability in water as compared to a non-particulate detergent
product having a density of at least about 1000 g/l but not having
the flow aid.
6. The process of claim 1 wherein the water-dispersible
non-particulate detergent product has in a range of from about 5%
to about 50% greater dispersability in water as compared to a
non-particulate detergent product having a density of at least
about 1000 g/l but not having the flow aid.
7. The process of claim 1 wherein the water-dispersible
non-particulate detergent product has at least about 10% greater
dispersibility in water as compared to a non-particulate detergent
product having a density of at least about 1000 g/l and having the
flow aid in an amount less than about 1% by weight of the
particulate detergent composition.
8. The process of claim 1 wherein the water-dispersible
non-particulate detergent product has at least about 25% greater
dispersability in water as compared to a non-particulate detergent
product having a density of at least about 1000 g/l and having the
flow aid in an amount less than about 2% by weight of the
particulate detergent composition.
9. The process of claim 1 wherein the water-dispersible
non-particulate detergent product has at least about 50% greater
dispersability in water as compared to a non-particulate detergent
product having a density of at least about 1000 g/l and having the
flow aid in an amount less than about 5% by weight of the
particulate detergent composition.
10. The process of claim 1 wherein the flow aid is in the form of
porous carrier particles.
11. The process of claim 10 wherein the porous carrier particles
are selected from the group consisting of amorphous silicates,
crystalline nonlayered silicates, layered silicates, calcium
carbonates, calcium/sodium carbonate double salts, sodium
carbonates, clays, zeolites, sodalites, alkali metal phosphates,
macroporous zeolites, chitin microbeads, carboxyalkylcelluloses,
carboxylalkylstarches, cyclodextrins, porous starches and mixtures
thereof.
12. The process of claim 10 wherein the porous carrier particles
are selected from the group consisting of Zeolite A, Zeolite X,
Zeolite Y, Zeolite P, Zeolite MAP and mixtures thereof.
13. The process of claim 1 wherein the step of providing a
particulate detergent composition includes providing the detergent
composition having a bulk density of no greater than about 900
g/l.
14. The process of claim 1 wherein the step of providing a
particulate detergent composition includes providing the detergent
composition having a bulk density in the range of from about 600
g/l to about 850 g/l.
15. The process of claim 14 wherein the step of providing a
particulate detergent composition includes providing the detergent
composition having a bulk density in the range of from about 625
g/l to about 725 g/l.
16. The process of claim 1 wherein the water-dispersible
non-particulate detergent product has at least about 10% greater
dispersibility in water as compared to a non-particulate detergent
product having a density of at least about 1000 g/l and formed from
a particulate detergent composition having a bulk density no
greater than 700 g/l, when the flow aid is added in an amount
greater than about 1% by weight of the particulate detergent
composition and when the particulate detergent composition has a
bulk density no greater than 700 g/l.
17. The process of claim 1 wherein the flow aid is in the form of a
powder homogeneously mixed in the particulate detergent
composition.
18. The process of claim 17 wherein the flow aid substantially
covers the surface of the particulate detergent composition.
19. A method of laundering fabric materials in a washing machine,
comprising the steps of: a) providing a flexible porous bag adapted
for receiving a non-particulate detergent product; b) providing a
non-particulate detergent product; c) placing the non-particulate
detergent product within the flexible porous bag; and d) placing
the flexible porous bag containing the detergent product in the
washing machine with the fabric materials to be washed; wherein the
flexible porous bag is adapted for permitting entry of an aqueous
washing medium through the bag, thereby dissolving the
non-particulate detergent product placed therein, into the aqueous
washing medium, and releasing a resultant wash solution from inside
of the bag to outside of the bag into the aqueous wash medium
during a wash cycle.
20. The method of claim 19 wherein the particulate detergent
product has a density of at least 1000 g/l.
21. A method of laundering soiled clothes comprising the step of
immersing the soiled clothes in an aqueous solution medium
containing an effective amount of a non-particulate detergent
product made by a process according to claim 1.
22. A water-dispersible non-particulate detergent product,
comprising: a core formed by compacting a particulate detergent
composition to a density of at least about 1000 g/l, the
particulate detergent composition having a bulk density in a range
of from about 600 g/l to about 850 g/l, and the particulate
detergent composition comprising a flow aid in a range of from
about 0.1% to about 25% by weight of the particulate detergent
composition.
23. The water-dispersible non-particulate detergent product of
claim 22 wherein the water-dispersible non-particulate detergent
product has at least about 5% greater dispersibilty in water as
compared to another non-particulate detergent product having a
density of at least about 1000 g/l but not having the flow aid.
24. The water-dispersible non-particulate detergent product of
claim 22 wherein the flow aid is zeolite.
25. A process for producing a water-dispersible non-particulate
detergent product, comprising the steps of: a) providing a
particulate detergent composition, wherein the particulate
detergent composition is a mixture of a spray dried detergent and
an agglomeration detergent comprising a bleaching agent, present in
a weight ratio in a range of from about 40:60 to about 80:20, spray
dried:agglomeration detergent, the final bulk density of the
detergent composition being no greater than about 900 g/l; b)
adding a flow aid to the particulate detergent composition in a
range of from about 0.1% to about 25% by weight of the particulate
detergent composition; and c) compacting the particulate detergent
composition having the flow aid by applying a pressure in an amount
sufficient to form the water-dispersible non-particulate detergent
product having a density of at least about 1000 g/l.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of Parent application Ser.
No. 09/674,000, filed Oct. 25, 2000 (Attorney Docket No. 7128)
which claims priority under 35 U.S.C. .sctn.119(e) to U.S.
Provisional Application Serial No. 60/083,264, filed Apr. 27, 1998
(Attorney Docket No. 7128P).
TECHNICAL FIELD
[0002] The present invention relates to detergent compositions in
non-particulate form. More particularly, the invention relates to a
process for improving the dispersibility of a non-particulate
detergent composition, e.g., tablet, block or bar, in water, by
enabling the manufacture of a non-particulate detergent product
that sinks in water and rapidly disintegrates and dissolves in
water
BACKGROUND OF THE INVENTION
[0003] Non-particulate detergents are an alternative to granular or
particulate forms of detergents for simplifying the dosing of such
detergents for automatic washing machines, such as laundry or
dishwashing machines. Such non-particulate detergents are usually
supplied in the form of bars, tablets or briquettes. Such
non-particulate detergents not only prevent spillage of the
detergent composition but also eliminate the need for the consumer
to estimate the correct dosage of the detergent composition per
wash. Further, such non-particulate detergents also minimize the
contact by the consumer with the detergent.
[0004] An important factor for successful performance of a
non-particulate detergent is its ability to dissolve in the washing
machine in a controlled manner according to a desired dissolution
profile during the program cycle of the machine. Another important
performance factor is that the non-particulate detergent should be
hard enough to facilitate easy handling of the detergent prior to
use, so that it does not inadvertently lose its structure, crumble,
or deteriorate, both during the packaging, transport and storage
and during handling by the end consumer prior to actual use. Such
performance aspects are an important feature of the non-particulate
detergent, and although they are not necessarily the focus of the
present invention, they are inherently a part of the background of
the present invention.
[0005] Additionally, a very desirable feature of a non-particulate
detergent, such as for example, a tablet, is its ability to sink in
water and rapidly disperse in water to form a wash solution. In
order to sink in water, a detergent tablet must have a density
greater than 1000 g/l and in order to disperse in water, a
detergent tablet must be able to break up in water. However, when
laundry tablets are made from low bulk density detergents, such as
those made by spray dried processes, wherein the detergent powder
has a bulk density less than about 650 g/l, the problem frequently
encountered is that the force required to compact the detergent
powder into tablets having a density of at least 1000 g/l is so
high that the detergent tablets do not readily disperse in water.
This problem is further escalated by the fact that detergent
powders made from spray dried processes tend to be more porous and
sticky. Thus when these detergent powders are pressed into tablets
having a density of at least 1000 g/l, the powder particles stick
together and consequently the tablet does not readily break up and
dissolve in water. Conversely, if the tablets made from low bulk
density detergent powders are compacted using a lower force, they
generally disperse in water but at a slower rate because they have
a density less than 1000 g/l and thus tend to float in water before
fully dispersing in water.
[0006] The above problem is usually not encountered when making
detergent tablets from a detergent powder made by agglomeration
processes because detergent powders made by agglomeration processes
usually have a bulk density in a range of about 700 g/l to about
850 g/l and consequently, the force required to compress the powder
into a tablet having a density of at least 1000 g/l is not so high.
Thus detergent tablets made by compacting detergent powders made
from agglomeration process usually sink in water. However,
agglomeration process detergents or "agglomerates", which
inherently have higher density than spray dried process detergents
or "spray dried granules", generally exhibit slower dissolution
rates in water, as compared to spray dried granules.
[0007] Thus the production of detergent tablets is a complex
matter. It involves more than the mere selection of components or
the compression of a particular detergent composition into a
tablet. The tablet must be capable of withstanding the shocks of
packaging, handling and distribution without crumbling. In other
words the tablet must be strong. But the tablet must also have a
satisfactory rate of disintegration when immersed in water. The
tablets known so far have generally shown too long a disintegration
time, in favor of their strength, or they have had a very low
strength, in favor of their shorter disintegration time.
[0008] It is highly desirable to have a laundry detergent tablet
with a core which is formed by compressing a particulate material
which has a detersive surfactant and a builder and wherein the
particulate material is processed in a manner so as to make the
individual particles sticky enough to stay together when the
material is compressed into a tablet form, yet not too sticky to
not disintegrate rapidly when immersed in water. This becomes a
very challenging problem in light of the additional desirable
requirement that the detergent tablet, after compaction, have a
density of at least 1000 g/l so that it sinks in water.
[0009] This kind of a tablet performance has heretofore not been
available and this level of performance requires not only careful
selection of the type of detergent that makes up the core, but also
requires novel ways to surface treat the detergent particles prior
to compaction so as have just the right amount of stickiness. The
present invention overcomes the problems as outlined above.
BACKGROUND ART
[0010] The prior art is replete with methods of forming tablets and
coating tablets.
[0011] One approach has been to use acetate salt to improve the
dissolution rate of detergents compressed in the form of tablets.
EP-A-0002293, published on Jun. 13, 1979, discloses detergent
tablets containing hydrated salt. The preferred hydrate salt is a
mixture of sodium acetate trihydrate and sodium metaborate
tetrahydrate.
[0012] Another approach known in the art is to use effervescent
aids to improve tablet disintegration. CA-A-2040307 discloses
laundry detergent tablets comprising anionic surfactants mixed with
sodium carbonate and citric acid.
[0013] As far as coated tablets are concerned, GB-A-0 989 683,
published on Apr. 22, 1965, discloses a process for preparing a
particulate detergent from surfactants and inorganic salts;
spraying on water-soluble silicate; and pressing the detergent
particles into a solid form-retaining tablet. Finally a readily
water-soluble organic film-forming polymer (for example, polyvinyl
alcohol) provides a coating to make the detergent tablet resistant
to abrasion and accidental breakage.
[0014] European publication, EP-A-0 002 293, published on Jun. 13,
1979, discloses a tablet coating comprising hydrated salt such as
acetate, metaborate, orthophosphate, tartrate, and sulphate.
Another European publication, EP-A-0 716 144, published on Jun. 12,
1996, also discloses laundry detergent tablets with water-soluble
coatings which may be organic polymers including acrylic/maleic
co-polymer, polyethylene glycol, PVPVA, and sugar.
SUMMARY OF THE INVENTION
[0015] The invention meets the needs above by providing a process
for producing a water-dispersible non-particulate detergent
product. Specifically, in one aspect of the present invention, the
process comprises the step of providing a particulate detergent
composition. The process further includes the step of adding a flow
aid to the particulate detergent composition in a range of from
about 0.1% to about 25% by weight of the particulate detergent
composition. The process then includes the step of compacting the
particulate detergent composition having the flow aid by applying a
pressure in an amount sufficient to form the water-dispersible
non-particulate detergent product having a density of at least
about 1000 g/l.
[0016] In another aspect of the present invention, a method of
laundering fabric materials in a washing machine is provided. The
method includes the steps of providing a flexible porous bag
adapted for receiving a non-particulate detergent product,
providing a non-particulate detergent product, placing the
non-particulate detergent product within the flexible porous bag,
and placing the flexible porous bag containing the detergent
product in the washing machine with the fabric materials to be
washed. The flexible porous bag is adapted for permitting entry of
an aqueous washing medium through the bag, thereby dissolving the
non-particulate detergent product placed therein, into the aqueous
washing medium, and releasing a resultant wash solution from inside
of the bag to outside of the bag and into the aqueous wash medium
during a wash cycle.
[0017] In yet another aspect of the present invention, a method of
laundering soiled clothes includes the step of immersing the soiled
clothes in an aqueous medium containing an effective amount of a
non-particulate detergent product made by a process which includes
the steps of providing a particulate detergent composition, adding
a flow aid to the particulate detergent composition in a range of
from about 0.1% to about 25% by weight of the particulate detergent
composition and compacting the particulate detergent composition
having the flow aid by applying a pressure in an amount sufficient
to form the water-dispersible non-particulate detergent product
having a density of at least about 1000 g/l.
[0018] In yet another aspect of the present invention, a
water-dispersible non-particulate detergent product is disclosed.
The product includes a core formed by compacting a particulate
detergent composition to a density of at least about 1000 g/l. The
particulate detergent composition has a bulk density in a range of
from about 600 g/l to about 850 g/l. The particulate detergent
composition comprises a flow aid in a range of from about 0.1% to
about 25% by weight of the particulate detergent composition.
DETAILED DESCRIPTION OF THE INVENTION
Process
[0019] In the preferred embodiment of the present invention, the
process includes the step of providing a particulate detergent
composition.
The Particulate Detergent Composition
[0020] The term "particulate" as used herein means forms such as
powders, granules, particles, flakes and other similar particulate
forms that are capable of being compacted into a more dense
non-particulate form.
[0021] In particular for laundry tablets, detergent particles
having ingredients such as builder and surfactant can be
spray-dried in a conventional manner and then compacted at a
suitable pressure. The surfactants and builders normally provide a
substantial part of the cleaning power of the tablet. The term
"builder" is intended to mean all materials which tend to remove
calcium ion from solution, either by ion exchange, complexation,
sequestration or precipitation.
[0022] The particulate material used for making the detergent
tablet provided in this invention can be made by any particulation
or granulation process. An example of such a process is spray
drying (in a co-current or counter current spray drying tower)
which typically gives "spray-dried" detergent granules having low
bulk densities of 600 g/l or lower. Particulate materials of higher
density can be prepared by granulation and densification in a high
shear batch mixer/granulator or by a continuous granulation and
densification process (e.g. using Lodige.RTM. CB and/or Lodige.RTM.
KM mixers). Other suitable processes include fluid bed processes,
compaction processes (e.g. roll compaction), extrusion, as well as
any particulate material made by any chemical process like
flocculation, crystallization sentering, etc. The individual
particles can also be in any other form, such as for example,
particle, granule, sphere or grain.
[0023] The particulate materials may be mixed together by any
conventional means, for example, a concrete mixer, Nauta mixer,
ribbon mixer or any other. Alternatively the mixing process may be
carried out continuously by metering each component by weight on to
a moving belt, and blending them in one or more drum(s) or
mixer(s). A liquid spray-on to the mix of particulate materials
(e.g. non-ionic surfactants) may be carried out. Other liquid
ingredients may also be sprayed on to the mix of particulate
materials either separately or premixed. For example perfume and
slurries of optical brighteners may be sprayed. A finely divided
flow aid (dusting agent such as zeolites, carbonates, silicas) can
be added to the particulate materials after spraying the non-ionic,
preferably towards the end of the process, to make the mix less
sticky.
[0024] The detergent particles can be made by an agglomerate
process comprising the steps of:
[0025] i) admixing one or more detergent surfactants, a perborate
component and an acid source and optionally other detergent
ingredients to form a mixture; and
[0026] ii) agglomerating the mixture to form agglomerated particles
or "agglomerates".
[0027] Typically, such an agglomeration process involves mixing an
effective amount of powder, including the acid source, with a high
active surfactant paste in one or more agglomerators such as a pan
agglomerator, a Z-blade mixer or more preferably in-line mixers,
preferably two, such as those manufactured by Schugi (Holland) BV,
29 Chroomstraat 8211 AS, Lelystad, Netherlands, and Gebruder Lodige
Maschinenbau GmbH, D-4790 Paderborn 1, Elsenerstrasse 7-9, Postfach
2050, Germany. Preferably a high shear mixer is used, such as a
Lodige CB (Trade Name). Most preferably, a high shear mixer is used
in combination with a low shear mixer, such as a Lodige CB (Trade
Name) and a Lodige KM (Trade name) or Schugi KM (Trade Name).
Optionally, only one or more tow shear mixer are used. Preferably,
the agglomerates are thereafter dried and/or cooled.
[0028] Another agglomeration process involves mixing of various
components of the final agglomerate in different stages, using a
fluidized bed. For example, a preferred particulate detergent in
accordance with the present invention can be agglomerated by
addition, preferably by spraying on, of nonionic, anionic
surfactants and optionally a wax, or mixtures thereof, to the acid
source in powdered form and other optional ingredients. Then,
additional components, including the perborate bleach and optinally
the alkali source or part thereof, can be added and agglomerated in
one or more stages, thus forming the final agglomerate
particle.
[0029] The agglomerates may take the form of flakes, prills,
marumes, noodles, ribbons, but preferably take the form of
granules. A preferred way to process the particles is by
agglomerating powders (e.g. aluminosilicate, carbonate) with high
active surfactant pastes and to control the particle size of the
resulting agglomerates within specified limits. Typical particle
sizes are from 0.10 mm to 5.0 mm in diameter, preferably from 0.25
mm to 3.0 mm in diameter, most preferably from 0.40 mm to 1.00 mm
in diameter. Typically, the "agglomerates" have a bulk density
desirably, of at least 700 g/l and preferably, in a range of from
about 700 g/l to about 900 g/l.
[0030] A high active surfactant paste comprising a mix of,
typically, from 50% by weight to 95% by weight, preferably 70% by
weight to 85% by weight of surfactant, and optionally it can
contain an appropriate acid source. The paste may be pumped into
the agglomerator at a temperature high enough to maintain a
pumpable viscosity, but low enough to avoid degradation of the
anionic surfactants used. An operating temperature of the paste of
50.degree. C. to 80.degree. C. is typical. Such pastes and methods
for making and processing such pastes is for example described in
WO 93/03128. In an especially preferred embodiment of the present
invention, the detergent particles made by agglomeration process
have a bulk density of greater than about 600 g/l and the detergent
is in the form of powder or a granulate.
[0031] In the preferred embodiment of the present invention, the
particulate detergent composition is a mixture of spray dried
process and agglomeration process detergents, such that the final
bulk density of the detergent composition is in a range of
desirably, no greater than about 900 g/l, more desirably, in a
range of from about 600 g/l to about 850 g/l, and preferably, in a
range of from about 625 g/l to about 725 g/l. These ranges of bulk
density are desirable because if the bulk density of the
particulate detergent from which the tablet is to be compressed is
greater than about 900 g/l, then the solubility of the detergent
tablet will be detrimentally affected. A bulk density less than
about 600 g/l is undesirable because at values less than about 600
g/l, the amount of pressure required to form a detergent tablet
having a density of at least 1000 g/l is so high that the tablet
will not break up easily in water and will not dissolve
rapidly.
[0032] To achieve the desired bulk densities as set forth above,
the particulate detergent composition contains selected amounts of
spray dried granules and detergent agglomerates in an optimum
proportion. In this regard, the composition comprises desirably
from about 40% to about 80%, preferably from about 40% to about
60%, and more preferably from about 45% to about 55%, by weight, of
spray dried. Desirably, the composition includes from about 20% to
about 60%, preferably from about 40% to about 60%, and more
preferably from about 45% to about 55%, by weight, of
agglomerates.
Dry Detergent Material
[0033] The starting dry detergent material of the present process
preferably comprises materials selected from the group consisting
of carbonates, sulfates, carbonate/sulfate complexes,
tripolyphosphates, tetrasodium pyrophosphate, citrates,
aluminosilicates, cellulose-based materials and organic synthetic
polymeric absorbent gelling materials. More preferably, the dry
detergent material is selected from the group consisting of
aluminosilicates, carbonates, sulfates, carbonate/sulfate
complexes, and mixtures thereof. Most preferably, the dry detergent
material comprise a detergent aluminosilicate builder which are
referenced as aluminosilicate ion exchange materials and sodium
carbonate.
[0034] The aluminosilicate ion exchange materials used herein as a
detergent builder preferably have both a high calcium ion exchange
capacity and a high exchange rate. Without intending to be limited
by theory, it is believed that such high calcium ion exchange rate
and capacity are a function of several interrelated factors which
derive from the method by which the aluminosilicate ion exchange
material is produced. In that regard, the aluminosilicate ion
exchange materials used herein are preferably produced in
accordance with Corkill et al, U.S. Pat. No. 4,605,509 (Procter
& Gamble), the disclosure of which is incorporated herein by
reference.
[0035] Preferably, the aluminosilicate ion exchange material is in
"sodium" form since the potassium and hydrogen forms of the instant
aluminosilicate do not exhibit the as high of an exchange rate and
capacity as provided by the sodium form. Additionally, the
aluminosilicate ion exchange material preferably is in over dried
form so as to facilitate production of crisp detergent agglomerates
as described herein. The aluminosilicate ion exchange materials
used herein preferably have particle size diameters which optimize
their effectiveness as detergent builders. The term "particle size
diameter" as used herein represents the average particle size
diameter of a given aluminosilicate ion exchange material as
determined by conventional analytical techniques, such as
microscopic determination and scanning electron microscope (SEM).
The preferred particle size diameter of the aluminosilicate is from
about 0.1 micron to about 10 microns, more preferably from about
0.5 microns to about 9 microns. Most preferably, the particle size
diameter is from about 1 microns to about 8 microns.
[0036] Preferably, the aluminosilicate ion exchange material has
the formula
Na.sub.z[(AlO.sub.2).sub.z.(SiO.sub.2).sub.y]xH.sub.2O
[0037] wherein z and y are integers of at least 6, the molar ratio
of z to y is from about 1 to about 5 and x is from about 10 to
about 264. More preferably, the aluminosilicate has the formula
Na.sub.12[(AlO.sub.2).sub.12.(SiO.sub.2).sub.12]xH.sub.2O
[0038] wherein x is from about 20 to about 30, preferably about 27.
These preferred aluminosilicates are available commercially, for
example under designations Zeolite A, Zeolite B and Zeolite X.
Alternatively, naturally-occurring or synthetically derived
aluminosilicate ion exchange materials suitable for use herein can
be made as described in Krummel et al, U.S. Pat. No. 3,985,669, the
disclosure of which is incorporated herein by reference.
[0039] The aluminosilicates used herein are further characterized
by their ion exchange capacity which is at least about 200 mg
equivalent of CaCO.sub.3 hardness/gram, calculated on an anhydrous
basis, and which is preferably in a range from about 300 to 352 mg
equivalent of CaCO.sub.3 hardness/gram. Additionally, the instant
aluminosilicate ion exchange materials are still further
characterized by their calcium ion exchange rate which is at least
about 2 grains Ca.sup.++/gallon/minute/-gram/gallo- n, and more
preferably in a range from about 2 grains
Ca.sup.++/gallon/minute/-gram/gallon to about 6 grains
Ca.sup.++/gallon/minute/-gram/gallon.
[0040] Additionally, those builder materials discussed previously
as an optional coating agent can be used herein. These particular
builder materials have the formula
(M.sub.x).sub.iCa.sub.y(CO.sub.3).sub.z wherein x and i are
integers from 1 to 15, y is an integer from 1 to 10, z is an
integer from 2 to 25, M.sub.i are cations, at least one of which is
a water-soluble, and the equation .SIGMA..sub.i=.sub.1-15(x.sub.i
multiplied by the valence of M.sub.i)+2y=2z is satisfied such that
the formula has a neutral or "balanced" charge. Additional details
and examples of these builder materials have been set forth
previously and are incorporated herein by reference. Preferably,
these builder materials are selected from the group consisting of
Na.sub.2Ca(CO.sub.3).sub.2, K.sub.2Ca(CO.sub.3).sub.2,
Na.sub.2Ca.sub.2(CO.sub.3).sub.3, NaKCa(CO.sub.3).sub.2,
NaKCa.sub.2(CO.sub.3).sub.3, K.sub.2Ca.sub.2(CO.sub.3).sub.3, and
combinations thereof.
Adjunct Detergent Ingredients
[0041] The starting dry detergent material in the present process
can include additional detergent ingredients and/or, any number of
additional ingredients can be incorporated in the detergent
composition during subsequent steps of the present process. These
adjunct ingredients include other detergency builders, bleaches,
bleach activators, suds boosters or suds suppressers, anti-tarnish
and anticorrosion agents, soil suspending agents, soil release
agents, germicides, pH adjusting agents, non-builder alkalinity
sources, chelating agents, smectite clays, enzymes,
enzyme-stabilizing agents and perfumes. See U.S. Pat. No.
3,936,537, issued Feb. 3, 1976 to Baskerville, Jr. et al.,
incorporated herein by reference.
[0042] Other builders can be generally selected from the various
water-soluble, alkali metal, ammonium or substituted ammonium
phosphates, polyphosphates, phosphonates, polyphosphonates,
carbonates, borates, polyhydroxy sulfonates, polyacetates,
carboxylates, and polycarboxylates. Preferred are the alkali metal,
especially sodium, salts of the above. Preferred for use herein are
the phosphates, carbonates, C.sub.10-18 fatty acids,
polycarboxylates, and mixtures thereof. More preferred are sodium
tripolyphosphate, tetrasodium pyrophosphate, citrate, tartrate
mono- and di-succinates, and mixtures thereof (see below).
[0043] In comparison with amorphous sodium silicates, crystalline
layered sodium silicates exhibit a clearly increased calcium and
magnesium ion exchange capacity. In addition, the layered sodium
silicates prefer magnesium ions over calcium ions, a feature
necessary to insure that substantially all of the "hardness" is
removed from the wash water. These crystalline layered sodium
silicates, however, are generally more expensive than amorphous
silicates as well as other builders. Accordingly, in order to
provide an economically feasible laundry detergent, the proportion
of crystalline layered sodium silicates used must be determined
judiciously.
[0044] The crystalline layered sodium silicates suitable for use
herein preferably have the formula
NaMSi.sub.xO.sub.2x+1.yH.sub.2O
[0045] wherein M is sodium or hydrogen, x is from about 1.9 to
about 4 and y is from about 0 to about 20. More preferably, the
crystalline layered sodium silicate has the formula
NaMSi.sub.2O.sub.5.yH.sub.2O
[0046] wherein M is sodium or hydrogen, and y is from about 0 to
about 20. These and other crystalline layered sodium silicates are
discussed in Corkill et al, U.S. Pat. No. 4,605,509, previously
incorporated herein by reference.
[0047] Specific examples of inorganic phosphate builders are sodium
and potassium tripolyphosphate, pyrophosphate, polymeric
metaphosphate having a degree of polymerization of from about 6 to
21, and orthophosphates. Examples of polyphosphonate builders are
the sodium and potassium salts of ethylene diphosphonic acid, the
sodium and potassium salts of ethane 1-hydroxy-1, 1-diphosphonic
acid and the sodium and potassium salts of ethane,
1,1,2-triphosphonic acid. Other phosphorus builder compounds are
disclosed in U.S. Pat. Nos. 3,159,581; 3,213,030; 3,422,021;
3,422,137; 3,400,176 and 3,400,148, all of which are incorporated
herein by reference.
[0048] Examples of nonphosphorus, inorganic builders are
tetraborate decahydrate and silicates having a weight ratio of
SiO.sub.2 to alkali metal oxide of from about 0.5 to about 4.0,
preferably from about 1.0 to about 2.4. Water-soluble,
nonphosphorus organic builders useful herein include the various
alkali metal, ammonium and substituted ammonium polyacetates,
carboxylates, polycarboxylates and polyhydroxy sulfonates. Examples
of polyacetate and polycarboxylate builders are the sodium,
potassium, lithium, ammonium and substituted ammonium salts of
ethylene diamine tetraacetic acid, nitrilotriacetic acid,
oxydisuccinic acid, mellitic acid, benzene polycarboxylic acids,
and citric acid.
[0049] Polymeric polycarboxylate builders are set forth in U.S.
Pat. No. 3,308,067, Diehl, issued Mar. 7, 1967, the disclosure of
which is incorporated herein by reference. Such materials include
the water-soluble salts of homo- and copolymers of aliphatic
carboxylic acids such as maleic acid, itaconic acid, mesaconic
acid, fumaric acid, aconitic acid, citraconic acid and methylene
malonic acid. Some of these materials are useful as the
water-soluble anionic polymer as hereinafter described, but only if
in intimate admixture with the non-soap anionic surfactant.
[0050] Other suitable polycarboxylates for use herein are the
polyacetal carboxylates described in U.S. Pat. No. 4,144,226,
issued Mar. 13, 1979 to Crutchfield et al, and U.S. Pat. No.
4,246,495, issued Mar. 27, 1979 to Crutchfield et al, both of which
are incorporated herein by reference. These polyacetal carboxylates
can be prepared by bringing together under polymerization
conditions an ester of glyoxylic acid and a polymerization
initiator. The resulting polyacetal carboxylate ester is then
attached to chemically stable end groups to stabilize the
polyacetal carboxylate against rapid depolymerization in alkaline
solution, converted to the corresponding salt, and added to a
detergent composition. Particularly preferred polycarboxylate
builders are the ether carboxylate builder compositions comprising
a combination of tartrate monosuccinate and tartrate disuccinate
described in U.S. Pat. No. 4,663,071, Bush et al., issued May 5,
1987, the disclosure of which is incorporated herein by
reference.
[0051] Bleaching agents and activators are described in U.S. Pat.
No. 4,412,934, Chung et al., issued Nov. 1, 1983, and in U.S. Pat.
No. 4,483,781, Hartman, issued Nov. 20, 1984, both of which are
incorporated herein by reference. Chelating agents are also
described in U.S. Pat. No. 4,663,071, Bush et al., from Column 17,
line 54 through Column 18, line 68, incorporated herein by
reference. Suds modifiers are also optional ingredients and are
described in U.S. Pat. Nos. 3,933,672, issued Jan. 20, 1976 to
Bartoletta et al., and 4,136,045, issued Jan. 23, 1979 to Gault et
al., both incorporated herein by reference.
[0052] Suitable smectite clays for use herein are described in U.S.
Pat. No. 4,762,645, Tucker et al, issued Aug. 9, 1988, Column 6,
line 3 through Column 7, line 24, incorporated herein by reference.
Suitable additional detergency builders for use herein are
enumerated in the Baskerville patent, Column 13, line 54 through
Column 16, line 16, and in U.S. Pat. No. 4,663,071, Bush et al,
issued May 5, 1987, both incorporated herein by reference.
[0053] The Non-Particulate Detergent Product
[0054] The detergent tablets can be prepared simply by mixing the
solid ingredients together and compressing the mixture in a
conventional tablet press as used, for example, in the
pharmaceutical industry.
[0055] The detergent tablets provided can be made in any size or
shape and are desirably surface treated with a flow aid according
to the present invention. The detergent tablets provided may be
manufactured by using any compacting process, such as tabletting,
briquetting, or extrusion, preferably tabletting. Suitable
equipment includes a standard single stroke or a rotary press (such
as Courtoy.RTM., Korch.RTM., Manesty.RTM., or Bonals.RTM.). As used
herein, the term "non-particulate detergent product" includes
physical shapes such as tablets, blocks, bars and the like.
Coating for Non-Particulate Detergent Product
[0056] In one embodiment, the tablets are coated with a coating in
order to provide mechanical strength and shock and chip resistance
to the compressed tablet core. The tablets are coated with a
coating that is substantially insoluble in water so that the tablet
does not absorb moisture, or absorbs moisture at only a very slow
rate. The coating is strong so that moderate mechanical shocks to
which the tablets are subjected during handling, packing and
shipping result in no more than very low levels of breakage or
attrition. Further, the coating is preferably brittle so that the
tablet breaks up when subjected to stronger mechanical shock.
Furthermore it is advantageous if the coating material is dissolved
under alkaline conditions, or is readily emulsified by surfactants.
This avoids the deposition of undissolved particles or lumps of
coating material on the laundry load. This may be important when
the coating material is completely insoluble (for example less than
1 g/l) in water.
[0057] As defined herein "substantially insoluble" means having a
very low solubility in water. This should be understood to mean
having a solubility in water at 25.degree. C. of less than 20 g/L,
preferably less than 5 g/l, and more preferably less than 1 g/l.
Water solubility is measured following the test protocol of ASTM
E1148-87 entitled, "Standard Test Method for Measurements of
Aqueous Solubility".
[0058] Suitable coating materials are fatty acids, adipic acid and
C8-C13 dicarboxylic acids, fatty alcohols, diols, esters and
ethers. Preferred fatty acids are those having a carbon chain
length of from C12 to C22 and most preferably from C18 to C22.
Preferred dicarboxylic acids are adipic acid (C6), suberic acid
(C8), azelaic acid (C9), sebacic acid (C 10), undecanedioic acid
(C11), dodecanedioic acid (C12) and tridecanedioic acid (C13).
Preferred fatty alcohols are those having a carbon chain length of
from C12 to C22 and most preferably from C14 to C18. Preferred
diols are 1,2-octadecanediol and 1,2-hexadecanediol. Preferred
esters are tristearin, tripalmitin, methylbehenate, ethylstearate.
Preferred ethers are diethyleneglycol mono hexadecylether,
diethyleneglycol mono octadecylether, diethyleneglycol mono
tetradecylether, phenylether, ethyl naphtyl ether, 2
methoxynaphtalene, beta naphtyl methyl ether and glycerol
monooctadecylether. Other preferred coating materials include
dimethyl 2,2 propanol, 2 hexadecanol, 2 octadecanone, 2
hexadecanone, 2, 15 hexadecanedione and 2 hydroxybenzyl alcohol.
The coating is a hydrophobic material having a melting point
preferably of from 40.degree. C. to 180.degree. C.
[0059] In the preferred embodiment, the coating can be applied in a
number of ways. Two preferred coating methods are a) coating with a
molten material and b) coating with a solution of the material. In
a), the coating material is applied at a temperature above its
melting point, and solidifies on the tablet. In b), the coating is
applied as a solution, the solvent being dried to leave a coherent
coating. The substantially insoluble material can be applied to the
tablet by, for example, spraying or dipping. Normally when the
molten material is sprayed on to the tablet, it will rapidly
solidify to form a coherent coating. When tablets are dipped into
the molten material and then removed, the rapid cooling again
causes rapid solidification of the coating material. Clearly
substantially insoluble materials having a melting point below
40.degree. C. are not sufficiently solid at ambient temperatures
and it has been found that materials having a melting point above
about 180.degree. C. are not practicable to use. Preferably, the
materials melt in the range from 60.degree. C. to 160.degree. C.,
more preferably from 70.degree. C. to 120.degree. C.
[0060] By "melting point" is meant the temperature at which the
material when heated slowly in, for example, a capillary tube
becomes a clear liquid. For most purposes, the coating forms from
1% to 10%, preferably from 1.5% to 5%, of the tablet weight.
Addition of Flow Aids
[0061] In the preferred embodiment, the process further includes
the step of adding a flow aid to the particulate detergent
composition in a range of from about 0.1% to about 25% by weight of
the particulate detergent composition.
[0062] As used herein, the term "flow aids" means any material
capable of being deposited on to the surface of detergent particles
so as to reduce the stickiness of the detergent particles and allow
them to flow freely. Flow aids could include porous carrier
particles selected from the group consisting of amorphous
silicates, crystalline nonlayer silicates, layer silicates, calcium
carbonates, calcium/sodium carbonate double salts, sodium
carbonates, clays, zeolites, sodalites, alkali metal phosphates,
macroporous zeolites, chitin microbeads, carboxyalkylcelluloses,
carboxyalkylstarches, cyclodextrins, porous starches and mixtures
thereof.
[0063] The preferred flow aids are zeolite A, zeolite X, zeolite Y,
zeolite P, zeolite MAP and mixtures thereof. The term "zeolite"
used herein refers to a crystalline aluminosilicate material. The
structural formula of a zeolite is based on the crystal unit cell,
the smallest unit of structure represented by
Mm/n[(AlO2)m(SiO2)y].xH2O
[0064] where n is the valence of the cation M, x is the number of
water molecules per unit cell, m and y are the total number of
tetrahedra per unit cell, and y/m is 1 to 100. Most preferably, y/m
is 1 to 5. The cation M can be Group IA and Group IIA elements,
such as sodium, potassium, magnesium, and calcium.
[0065] In the preferred embodiment of the present invention, the
flow aid is added in an amount in a range, desirably, from about
0.1% to about 25% by weight of the particulate detergent, more
desirably from about 1% to about 15% by weight, preferably from
about 1% to about 10% by weight, and most preferably in an amount
of about 5% by weight. It is undesirable to add more than 25% by
weight of the flow aid because too excessive a force would be
needed to make the detergent particles to stick together and stay
in a particulate form. Flow aid addition in an amount less than
about 0.1% by weight is also undesirable because little or no
reduction in the stickiness of the detergent particles would occur,
which upon compression into a particulate form would cause the
resultant detergent tablet to not disintegrate readily when placed
in water in a washing machine.
[0066] In one embodiment, the flow aids have a perfume adsorbed on
their surface before being deposited on the detergent particles.
Preferably, the flow aids are zeolites preferably containing less
than about 20% desorbable water, more preferably less than about 8%
desorbable water, and most preferably less than about 5% desorbable
water. Such materials may be obtained by first
activating/dehydrating by heating to about 150.degree. to
350.degree. C., optionally with reduced pressure (from about 0.001
to about 20 Torr). After activation, the perfume is slowly and
thoroughly mixed with the activated zeolite and, optionally, heated
to about 60.degree. C. for up to about 2 hours to accelerate
absorption equilibrium within the zeolite particles. The
perfume/zeolite mixture is then cooled to room temperature and is
in the form of a free-flowing powder. The term "perfume" is used to
indicate any odoriferous material which is subsequently released
into the aqueous bath and/or onto fabrics contacted therewith. The
perfume will most often be liquid at ambient temperatures. A wide
variety of chemicals are known for perfume uses, including
materials such as aldehydes, ketones and esters. More commonly,
naturally occurring plant and animal oils and exudates comprising
complex mixtures of various chemical components are known for use
as perfumes. The perfumes herein can be relatively simple in their
compositions or can comprise highly sophisticated complex mixtures
of natural and synthetic chemical components, all chosen to provide
any desired odor. Typical perfumes can comprise, for example,
woody/earthy bases containing exotic materials such as sandalwood,
civet and patchouli oil. The perfumes can be of a light floral
fragrance, e.g., rose extract, violet extract, and lilac. The
perfumes can also be formulated to provide desirable fruity odors,
e.g., lime, lemon, and orange. Any chemically compatible material
which exudes a pleasant or otherwise desirable odor can be used in
the perfumed compositions herein. Perfumes also include
pro-fragrances such as acetal pro-fragrances, ketal pro-fragrances,
ester pro-fragrances (e.g., digeranyl succinate), hydrolyzable
inorganic-organic pro-fragrances, and mixtures thereof. These
pro-fragrances may release the perfume material as a result of
simple hydrolysis, or may be ph-change-triggered pro-fragrances
(e.g., pH drop) or may be enzymatically releasable
pro-fragrances.
[0067] In the preferred embodiment, the amount of perfume adsorbed
on the carrier material, such as zeolite for example, is preferably
in the range of about 0.1% to about 50% by weight, more preferably
in the range of about 0.5% to about 25% by weight, and most
preferably in the range of about 1% to about 15% by weight of
zeolite powder.
Compaction of Particulate Detergent to Form Non-Particulate
Detergent Product
[0068] In the preferred embodiment, the process still further
includes the step of compacting the particulate detergent
composition having the flow aid by applying a pressure in an amount
sufficient to form the water-dispersible non-particulate detergent
product having a density of at least about 1000 g/l. It is
desirable to form a detergent tablet that has a density of at least
about 1000 g/l so that the tablet will sink in water. If the
density of the detergent tablet is less than about 1000 g/l, the
tablet will float when placed in the water in a washing machine and
this will detrimentally reduce the dissolution rate of the tablet
in the water. It is desirable to apply at least that much pressure
as is sufficient to compress the particulate detergent material to
form a tablet having a density of at least about 1000 g/l. Too
little a pressure will result in a compressed tablet with a density
less than about 1000 g/l.
EXAMPLE A
[0069] Detergent tablets are formed which have a flow aid deposited
on the detergent particles before such particles are compressed
into a tablet form, according to the following composition:
1 TABLE A.1 Ingredients % by weight Detergent particles 95.00 Flow
Aid (zeolite A) 5.00 Total 100.00
[0070] The detergent particles have the following composition:
2 TABLE A.2 Particulate detergent Ingredients % by weight C
.sub.12-16 linear alkylbenzene sulfonate 8.80 C .sub.14-15 alkyl
sulfate/C .sub.14-15 alkyl ethoxy sulfate 8.31 C .sub.12-13 alkyl
ethoxylate 1.76 polyacrylate (MW = 4500) 2.40 polyethylene glycol
(MW = 4000) 0.96 sodium sulfate 8.40 aluminosilicate 21.28 sodium
carbonate 16.80 protease enzyme 0.32 sodium perborate monohydrate
2.08 lipase enzyme 0.17 cellulase enzyme 0.08 NOBS extrudate 4.80
citric acid monohydrate 2.25 sodium bicarbonate 2.75 sodium acetate
15.00 free water 1.60 other minor ingredients (perfume etc.) 2.24
Total 100.00
[0071] The detergent tablet formed is coated with a coating
according to the following composition:
3 TABLE A.3 Ingredient % by weight Detergent tablet having flow aid
91.10 Coating: dodecanedioc acid 8.00 carboxymethyl cellulose 0.90
Total 100.00
[0072] The flow aid (zeolite) is added to the particulate detergent
composition and mixed by one of various methods, such as agitation
for example, in order to homogeneously mix the flow aid with the
detergent composition. Alternatively, the flow aid is sprayed on
the surface of detergent particle.
[0073] The tablets are formed by compressing the tablet ingredients
in a cylindrical die having a diameter of 55 mm using a laboratory
press having a trade name Carver Model 3912, to form a tablet
having a height of 20 mm. The formed tablets were then coated with
the protective coating by dipping the tablet into a molten bath of
the coating for about 3 seconds. The molten coating bath is
maintained at a temperature of about 145 degrees centigrade.
[0074] The term "NOBS extrudate" as used herein, is an acronym for
the chemical sodium nonanoyloxybenzene sulfonate, commercially
available from Eastman Chemicals, Inc. The carboxymethyl cellulose
used in the above example is commercially available from
Metsa-Serla and sold under the trade name, Nymcel ZSB-16.
Test for Determining Dispersibility in Water
[0075] The following method is used to measure the rate of
dispersion (ROD) of a detergent tablet expressed as percentage
residue remaining after "t" minutes, where "t" is 3, 5 and 10
minutes. The equipment used includes a 5000 ml glass beaker, a
stopwatch with alarm, an electrical stirrer with variable speed IKA
RW 20 DZM or equivalent, a cage made of perforated metal gauze
(diameter 52 mm, height 40 mm having 16 apertures each of about 2.5
mm square) and a weigh scale with accuracy of 0.1 grams.
[0076] The method includes the following steps: The beaker is
filled with 4000 ml (+/-50 ml) of distilled water at 20.degree. C.
(+/-1.degree. C.). The cage tester is mounted in the electrical
stirrer. A tablet with a known weight is placed in the cage and the
cage is connected to the stirrer. The cage is submerged in the
water with the cage suspended about half way down the beaker and
the stirrer is started at a fixed speed of 80 rpm. The stopwatch is
started. The stirrer is stopped after 3 minutes. The cage is lifted
out of the water and the tablet residue remaining in the cage is
weighed. The % residue is calculated with the following equation: 1
% residue = Tablet weight after t minutes Initial tablet weight
.times. 100
[0077] The remaining tablet is placed back in the cage and the
process is repeated for an additional 2 and 5 minutes to give yield
data for tablet dispersion after 3, 5 and 10 minutes.
[0078] As used herein, the term "dispersibility in water" is
defined as a measure of the % residue, as calculated above, after 3
minutes. In other words, for example, a detergent tablet which has
5% by weight less residue than another detergent tablet would be
deemed to have 5% greater dispersibility in water.
[0079] It has been unexpected and surprisingly discovered that the
non-particulate detergent product, e.g., a detergent tablet, has at
least about 5% greater dispersability in water as compared to
another non-particulate detergent product having a density of at
least about 1000 g/l but not formulated with a flow aid according
to this invention. It has also been unexpectedly found that the
water-dispersible non-particulate detergent product has at least
about 10% greater dispersability in water as compared to a
non-particulate detergent product having a density of at least
about 1000 g/l and having a flow aid in an amount less than about
1% by weight of the particulate detergent composition.
[0080] It has also been discovered that the water-dispersible
non-particulate detergent product formed by the process of the
present invention has at least about 25% greater dispersability in
water as compared to a non-particulate detergent product having a
density of at least about 1000 g/l and having a flow aid in an
amount less than about 2% by weight of the particulate detergent
composition.
[0081] In the preferred embodiment of the present invention, the
flow aid is added in an amount of about 5% by weight of the
particulate detergent composition. It has been unexpectedly
discovered that by doing so, the water-dispersible non-particulate
detergent product of the present invention has at least about 50%
greater dispersability in water as compared to another
non-particulate detergent product having a density of at least
about 1000 g/l and having the flow aid in an amount less than about
5% by weight of the particulate detergent composition.
[0082] In another embodiment of the present invention, a method of
laundering fabric materials in a washing machine includes the steps
of providing a flexible porous bag adapted for receiving a
non-particulate detergent product, providing a non-particulate
detergent product, placing the non-particulate detergent product
within the flexible porous bag, and placing the flexible porous bag
containing the detergent product in the washing machine with the
fabric materials to be washed.
[0083] The flexible porous bag is permeable to water and to the
washing medium and is thus adapted for permitting entry of an
aqueous washing medium through the bag, thereby dissolving the
non-particulate detergent product placed therein, into the aqueous
washing medium, and releasing a resultant wash solution from inside
of the bag to outside of the bag and into the aqueous wash medium
during a wash cycle.
[0084] The flexible porous bag is made of a material capable of
retaining the non-particulate detergent product without allowing it
to pass through until the detergent product has dissolved in the
washing medium. The bag is also made of a material capable of
withstanding the temperatures of washing laundry in a washing
machine.
[0085] The process of the invention may be applied not only to
non-particulate detergents but also to any non-particulate product
which is active during washing, such as, for example, bleaching
agents, such as agents releasing chlorine or active oxygen
(peroxygen compounds), bleaching catalysts, bleaching activators,
bactericides, foam regulators, whiteners, agents preventing the
re-deposition of soil, enzymes, softeners, agents capable of
removing grease stains or other constituents having no direct
effect on the soiling but capable of taking part in the laundry
washing process.
[0086] The flexible bag may be made from any material which offers
a sufficient resistance to water, such as a woven or non-woven
material produced from natural or synthetic fibers. For example,
the bag is formed of pure cotton either in the form of a fabric
with a mesh opening of less than about 0.5 mm or in the form of a
non-woven article with openings having a size in a range of from
about 0.5 mm to about 0.8 mm.
[0087] Accordingly, having thus described the invention in detail,
it will be obvious to those skilled in the art that various changes
may be made without departing from the scope of the invention and
the invention is not to be considered limited to what is described
in the specification.
* * * * *